1. Field of the Invention
The present invention relates to a corrugated cardboard box stacking device in a corrugated cardboard box making machine wherein thinly folded corrugated cardboard boxes successively transported from a folding section are stacked one by one, and then a group of the stacked boxes are discharged at once since it is necessary to bundle a predetermined number of the corrugated cardboard boxes for facilitating the handling of the boxes.
2. Description of Related Art
A conventional corrugated cardboard box stacking device generally has a structure as shown in FIG. 10. In other words, corrugated cardboard boxes A formed in the folding section E are fed one by one to the corrugated cardboard box stacking device in the horizontal direction, and then the boxes are forwarded onto a feed belt 52 passing through a pair of rotary screws 51 provided at left and right sides. Thereafter, they are advanced by the feed belt 52 and stopped by hitting a stopper 53 As a result, the front portion of the box A is supported on the feed belt 52 and both of the rear sides are supported on spiral vanes 51a of the rotary screws 51. The rotary screw 51 is provided with a spiral vane 51a which is wound around a multiplicity of times and the corrugated cardboard boxes A are stacked upward from lower portion in the area between the spiral vane 51a having a little space between each of the boxes. With rotation of the rotary screws 51, the corrugated cardboard box A is successively lifted and the boxes are also stacked on the top portion 51t of the rotary screws 51 and the top portion 53t of the back stopper 53 as shown in FIG. 10. When the number of corrugated cardboard boxes stacked on both of the top portions 51t,53t reached a predetermined number of sheets, a pusher bar 54 is advanced as shown by phantom line in FIG. 10 and a predetermined number of corrugated cardboard boxes A are moved at once toward discharge rollers 55. A stacked group of the corrugated cardboard boxes moved onto the discharge rollers 55 are conveyed to a predetermined location to be bundled thereat.
In the above-mentioned example of conventional device, however, there is a problem that when the pusher bar 54 is advanced, the box Ay supported on the uppermost of the rotary screws 51 is taken out together with the bottommost box Ax of a group of the corrugated cardboard boxes transported by the pusher bar 54 and the boxes exceeding the predetermined number are transported by the pusher bar 54.